Two months of settlement talks have failed to end a legal dispute over Xcel Energy's cancellation of a $400 million wind farm in North Dakota, the Minneapolis-based utility said Monday.

Xcel said in a court filing that it spent most of November and December "actively discussing settlement" with the project's developer, EnXco, even suspending legal work "so the settlement process would have a greater chance of success."

But the filing Monday said the talks failed, and that litigation in U.S. District Court in Minneapolis will continue.

EnXco, a U.S. affiliate of Paris-based EDF Energies Nouvelles, has sued Xcel, alleging breach of contract for dropping out of the 100-turbine Merricourt wind project almost a year ago.

Xcel quit amid concern about two endangered birds, the piping plover and the whooping crane, that are found on the project site in southeastern North Dakota.

But EnXco contends that bird-protection issues can be addressed and that Xcel simply wants to save money because wind-power prices dropped after it signed the deal in 2007.

In a statement, EnXco spokeswoman Sandi Briner said the company regrets that it couldn't reach common ground in the talks, but "we remain open to discussion and are in constant contact with Xcel.''

No construction is happening on the project, near Ellendale, N.D., but Briner said the company remains committed to it and is working with the U.S. Fish and Wildlife Service to address avian issues.

The project was approved by North Dakota regulators last June, but still needs a permit from federal officials in case a protected bird is killed by a turbine blade.

Xcel said pretrial legal work likely will involve questioning more than 25 people in transcribed depositions. The trial will likely occur late this year or early in 2013, Xcel said.